Novel Titanate Oxyhydrides (1): BaTiO_3-xH_x

Abstract

For mixed anion oxides, the least commonly encountered substitution is where the hydride anion (H^-) replaces oxygen to form an oxyhydride. Only a handful of oxyhydrides have been reported, so far. Here, we present an oxyhydride of BaTiO₃, as an O^2-/H^- solid solution with compositions up to up to BaTiO_2.4H_0.6. BaTiO_3-xH_x is electronically conducting, and stable in air and water at ambient conditions. Furthermore, the hydride species is exchangeable with hydrogen gas at 400°C. Such exchange implies diffusion of hydride, and interesting diffusion mechanisms specific to hydrogen may be at play.